Although antidepressants are the mainstay of treatment for depressed elderly, regimens are often problematic and undermined by high prescription drug costs. The new Medicare drug benefit represents an unprecedented opportunity to address these costs;however there are enormous pressures to contain expenditures by patient cost-sharing. Medication Therapy Management (MTM) programs will also be administered by pharmacists. It is unclear how these drug coverage changes, cost-containment strategies, and MTM programs will impact antidepressant use, quality, health, and economic outcomes in extremely vulnerable elderly with depression. After careful consideration of all reviewer comments of our first submission, we propose a multi-faceted approach using controlled time-series analyses of several large, representative databases, to shed light on the following Medicare drug coverage impacts: - Immediate changes in antidepressant use, including in important subgroups (e.g., with no prior drug coverage) and time periods (e.g., "Doughnut Holes" between initial coverage and catastrophic coverage). - Changes in antidepressant prescribing quality and whether any impacts differ depending upon the type of drug cost-sharing measures used? - Impacts on health outcomes experienced by antidepressant users, including the need for emergency care, hospitalizations, and nursing home admissions - Impacts on the most vulnerable elderly subgroups, such as those with low incomes, poor health status and functioning, and specific comorbidities. - Effectiveness and cost-effectiveness of MTM programs on elderly antidepressant users - Development of a policy simulation program to help policy makers predict the impacts of cost- containment measures on seniors who use antidepressants - Dissemination of results and recommendations to policy makers at the federal and state levels. Only with such information can necessary adaptations (e.g., to formulary, cost-sharing, and MTM programs) be made to improve the quality and outcomes of pharmacotherapies in susceptible and traditionally under-served elderly with depression.